Patent GB-936300-A (GB)
Title: System and apparatus for transmitting characters in hell or similar code for fascimile sheet printer reception
IPC: G11C17/02
Filed: 1959-12-22
Abstract: 936,300. Facsimile telegraphy. R. HELL. Dec. 22, 1959 [Dec. 27, 1958], No. 43504/59. Class 40 (3). In an arrangement for transmitting characters in Hell or similar code for facsimile sheetprinter reception, the pulse trains corresponding to those characters of a line of text which are to be transmitted in Hell or similar code are stored seriatim in one or the other of two pulse-operated line stores alternately, pulse trains representing a scanning row or band of a line of text in the direction thereof are successively derived from the filled store and such pulse trains are read and transmitted to be received by a facsimile sheet-printer seriatim row by row in the sequence in which they compose the line of text from top to bottom. A transmitter 1 produces from a tape 41 perforated according to the teleprinter (5, 6 or 7 unit) code selective pulses which are passed over a connection 2 to a decoder 3 having forty-eight outputs 4 corresponding to forty-seven characters or symbols and one for " space." The output over a connection 4 passes through one of an associated pair of gating switches 5, 6 to an associated store 7 or 8, each store comprising sixty-nine arrays of twenty-five ferro-magnetic storage members arranged in the form of a square so that a character is represented by selected dots in a 25-dot mosaic, and a line consists of sixtynine characters. Each output 4 is individually wired through the cores of the storage elements according to the configuration of the corresponding letter and a pulse from a timing counter 9 (or 9<SP>1</SP>) achieves the setting of those cores selected by the output 4. A pulse generator 17 controls the stepping of the transmitter 1 and of a counter 9 (or 9<SP>1</SP>) controlling, respectively, the passage of successive characters to the decoder 3 and the storage of the characters on the arrays 1 ... 69 in sequence. If, for example, the store 8 has been filled and transmission is taking place therefrom the gate switch 5 is in the conductive condition so that characters from the decoder 3 pass to the arrays 1 ... 69 of the store 7. The successive rows of storage elements of the sixty-nine arrays are scanned by pulses fed from a counter 23 (or 23<SP>1</SP>) having 483 operative steps and controlled from a pulse generator 44 operating at 3000 c.p.s. The five dot positions of each array 1 ... 69 are augmented by a preceding and subsequent pulse position to provide a spacing corresponding to two dot positions between successive characters, so that seven dot positions or pulses are required for each of the sixty-nine character positions. The pulses from the counter 23<SP>1</SP> produce from storage elements which have been set, pulses which are passed over line 31, conductive switch 30, amplifier 33 and modulator 34 to the output line 36. When the counter 23 (or 23<SP>1</SP>) has completed a cycle of 483 steps, it passes a pulse over conductor 24 to a six-position counter 25 of which the first five positions are allocated to the scanning of the five rows of storage elements, and the sixth position permits the feeding of the receiver sheet for the normal spacing between the lines of characters. When the counter 25 has been stepped to position six, a pulse via connection 28 changes over the switch members 29, 30 so that 29 becomes conductive and a pulse over lead 28<SP>1</SP> changes over the switch members 5, 6 so that the latter becomes conductive and the characters from the decoder 3 are passed to the store 8. In response to the signals for " figureshift," " letter-shift," " bell " and " who are you ? ", a pulse passes over conductor 40 to close a gate 16 to prevent a pulse from the generator 17 effecting the normal control of the arrays 1 ... 69 of the line-feed (L.F.) store 7 or 8 which is operative. When the line-feed (L.F.) combination is detected on the tape 41, the decoder 3 applies a pulse to the line 11 changing over the trigger 12 to produce a pulse at 13 which closes gates 14, 16 to the pulses from the generator 17 so that the tape 41 is not fed forward and the counters 9 or (9<SP>1</SP>) are not stepped so that no further characters are fed to the store which is being filled. When the scanning of the previously stored line of characters has been completed, the counter 25 passes a pulse over leads 28 so that switch members 29, 30 and 5, 6 are changed over and trigger switch 12 is restored to its normal condition in which the pulse is no longer present on output 13 so that gates 14, 16 are opened to the stepping pulses from the generator 17. The counters 9, 9<SP>1</SP> resume from the position reached when the L.F. signal.was detected and the signals subsequent to the L.F. signal are passed to the store for the subsequent line. When the L.F. signal is accompanied by carriage-return (C.R.) the above operations take place, and, in addition, the pulse on line 10 changes over a switch member 20 producing a pulse from differentiator 21 which restores the counters 9, 9<SP>1</SP> to their initial positions. The storage device, Fig. 2, shows two of the sixty-nine 25-element arrays of one of the stores threaded according to the configuration of the letter H by a conductor 49 connected to the H output 47 of the decoder 3 and carrying halfcurrent " write " pulses. Half-current " write " pulses are also passed in sequence from the terminals 1, 2 ... 69 of the counter 9, (9<SP>1</SP>) so that storage elements are selectively set to the " 1 " condition corresponding to the shape of the letter. The reading out of the successive rows of storage cores is effected by the counter 23 (23<SP>1</SP>) having 483 effective steps with two non- reading positions, such as 1 and 7, 8 and 14, ... 477 and 483, for each character to provide letter spacing in combination with the six position counter 25 providing half current " read " pulses for the rows 1 to 5 and a non-operative scanning position 6 to provide the normal spacing between lines.